From MusicBrainz Wiki

Thoughts on recording

I've spoken to the band about this, which includes one recording engineer, and all agree that a recording is a recording. The band go into the studio, record a track, it's mixed, that's the recording. It may be released on a CD, vinyl, cassette, digital download, it may appear on an album, or EP or a various compilation or as a single download, but it's still the same recording, to say it's different is nonsensical to all of us.

Different recording sessions produce different recordings, not how it's released.